A false-color picture taken in infrared light reveals features that cannot be seen in visible light. Hubble's unique infrared view pinpoints variations in the abundance and distribution of unknown water-bearing minerals on the planet. While it has been known for decades that small amounts of water-bearing minerals exist on the planet's surface, the reddish regions in this image indicate areas of enhanced concentrations of these as-yet-unidentified deposits. They are perhaps related to the water-rich history of this part of Mars. In particular, the large reddish region known as Mare Acidalium was the site of massive flooding early in Martian history. (NASA's Pathfinder spacecraft landed at the southern edge of this region in 1997.) This composite image was taken in July 1997 with Hubble's Near Infrared Camera and Multi-Object Spectrometer. Red corresponds to the strength of an absorption band detected near 1450 nanometers; green to the brightness of the surface in the near-infrared; and blue to topographic elevation, determined from Viking Orbiter data.